Solar light concentration plate

Abstract

A solar light concentration plate comprises a plurality of holograms diffracting incident light wherein each of the plurality of the holograms has a thickness, at least one intermediate light guide plate disposed between the plurality of the holograms, and a pair of external light guide plates disposed on outer surfaces of outermost holograms of the plurality of the holograms, wherein at least one of the pair of the external light guide plates has an inner surface and an outer surface inclined relative to the inner surface.

What is claimed is: 
     
       1. A solar light concentration plate comprising:
 a plurality of holograms diffracting incident light wherein the plurality of the holograms have different thicknesses; 
 wherein the plurality of the holograms comprises a first hologram and a second hologram, and the second hologram has a larger thickness and smaller wavelength selectively than the first hologram; 
 at least one intermediate light guide plate disposed between the plurality of the holograms; and 
 a pair of external light guide plates disposed on outer surfaces of outermost holograms of the plurality of the holograms, 
 wherein at least one of the pair of the external light guide plates has an inner surface, and an outer surface inclined relative to the inner surface. 
 
     
     
       2. The solar light concentration plate of  claim 1 , wherein an uppermost hologram of the outermost holograms of the plurality of holograms has larger angular selectivity than other holograms of the plurality of holograms. 
     
     
       3. The solar light concentration plate of  claim 1 , wherein the plurality of holograms diffract light having a wavelength falling within a range of wavelengths. 
     
     
       4. The solar light concentration plate of  claim 3 , wherein the predetermined range of wavelengths is about 10 nanometers to about 300 nanometers. 
     
     
       5. The solar light concentration plate of  claim 1 , wherein each of the external light guide plates has the outer surface inclined to the inner surface. 
     
     
       6. The solar light concentration plate of  claim 5 , wherein an angle made with the outer surfaces of the external light guide plates is about 1 degree to about 10 degrees. 
     
     
       7. The solar light concentration plate of  claim 1 , wherein the plurality of the holograms comprises phase difference holograms. 
     
     
       8. The solar light concentration plate of  claim 7 , wherein the thickness of the plurality of the hologram is equal to or greater than about 1 micron. 
     
     
       9. The solar light concentration plate of  claim 1 , wherein the at least one intermediate light guide plate include a transparent plastic film. 
     
     
       10. The solar light concentration plate of  claim 9 , wherein the plastic film may have a refractive index of about 1.5. 
     
     
       11. The solar light concentration plate of  claim 1 , wherein a total reflection angle for light toward air from the at least one intermediate light guide plate is about 42 degrees. 
     
     
       12. The solar light concentration plate of  claim 1 , wherein the plurality of the holograms and the pair of external light guide plates are attached with an index matching adhesive. 
     
     
       13. The solar light concentration plate of  claim 1 , wherein the plurality of the holograms is recorded with laser. 
     
     
       14. The solar light concentration plate of  claim 1 , wherein an optical fiber is connected to a thicker side of the solar light concentration plate. 
     
     
       15. The solar light concentration plate of  claim 1 , wherein a photoelectric conversion device is connected to a thicker side of the solar light concentration plate. 
     
     
       16. A method of guiding light using a solar light concentration plate, the method comprising;
 providing a plurality of holograms diffracting incident light wherein the plurality of the holograms have different thicknesses; 
 wherein the plurality of the holograms comprises a first hologram and a second hologram, and the second hologram has a larger thickness and smaller wavelength selectively than the first hologram; 
 disposing at least one intermediate light guide plate between the plurality of the holograms; and 
 disposing a pair of external light guide plates on outer surfaces of outermost holograms of the plurality of the holograms, 
 wherein at least one of the pair of the external light guide plates has an inner surface and an outer surface inclined relative to the inner surface. 
 
     
     
       17. The method of  claim 16 , wherein an uppermost hologram of the outermost holograms of the plurality of holograms has larger angular selectivity than other holograms of the plurality of holograms. 
     
     
       18. The method of  claim 16 , wherein the plurality of holograms diffract light having a wavelength falling within a range of wavelengths. 
     
     
       19. The method of  claim 16 , wherein the predetermined range of wavelengths is about 10 nanometers to about 300 nanometers. 
     
     
       20. The method of  claim 16 , wherein each of the external light guide plates has the outer surface inclined to the inner surface.